The electric bed is a new type of bed, where the shape of its bed surface is changeable according to user needs. In order to improve the comfort of the electric bed and further satisfy the user's comfort requirements, relevant manufacturers researched and developed many additional functions. One of these functions includes an ejector mechanism for head and waist positioning such as neck or lumbar support. Ejector mechanisms may allow neck support, lumbar support.
Chinese patent publication CN 201220387006 discloses an electric bed with head and waist ejector functions where a head ejector mechanism uses a composite structure of a hinge and a push rod. The ejected part has one end hinged with a bed board (frame) and another end driven by a linear motor so that the ejected part is ejected during rotation around the hinge joint. The bed board is a bed board frame from which the ejector mechanism protrudes. Thus, the bed board is referred to as the bed board (frame).
The lumbar or waist ejector mechanism uses a lifting pole driven by the motor and can rotate around a fixed point below the bed board (frame) to raise/drop the mattress for the waist, playing a role of supporting or massage.
Curvilinear movement achieves the above-mentioned ejector mechanism used in the prior art. The ejected part is not parallel to the original bed board (frame), so user experience can be poor in case of pinching. Additionally, the head ejector mechanism does not have massage function. The waist ejector mechanism also scrapes with the mattress due to its movement in a curve, thereby shortening the service life of the mattress.